chore: add Claude Code config alongside AGENTS.md

- CLAUDE.md imports AGENTS.md so both Claude Code and opencode share one
  source of truth for agent guidance
- .claude/settings.json allowlists common mvnw/git read commands
- .gitignore ignores personal .claude/settings.local.json

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: DrSatyr

.claude/settings.json

@@ -0,0 +1,11 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(./mvnw:*)",
+      "Bash(git status:*)",
+      "Bash(git diff:*)",
+      "Bash(git log:*)",
+      "Bash(git show:*)"
+    ]
+  }
+}

.gitignore

@@ -27,3 +27,6 @@ target/
 
 # OpenCode
 .opencode/
+
+# Claude Code (personal/local settings; shared config is CLAUDE.md -> AGENTS.md)
+.claude/settings.local.json

CLAUDE.md

@@ -0,0 +1,6 @@
+# CLAUDE.md
+
+Project guidance for agentic coding tools lives in a single shared file so that
+Claude Code, opencode, and other agents stay in sync. Read it here:
+
+@AGENTS.md